1. Field of the Invention
The present invention relates to an object information processing apparatus which is simple in construction and capable of recognizing environments by using distance information.
2. Description of the Prior Art
Various techniques for recognizing environments by using visual sensors have been studied heretofore. Most of such techniques simulate the functions of human visual recognition in which distributional characteristics of the brightness and coloring of the environments are extracted out of signals obtained with a television camera and the extracted characteristics are compared with stored informations to perform such functions. As an example, there is known in the art a method for determining what an object is by analyzing the shape, border lines, colors, and shading of the object using a camera. The method, however, requires time in the order of minutes in order to recognize even a simple object such as a building block. Thus, it is impossible to effect real time processing, which results in hardships of practical applications. Another method has been proposed (for example, refer to the Journal of the Institute of Television Engineers of Japan, Vol. 34, No. 3, 1980). In the method, the distribution of distances to an object is measured by radiating a light flux through a slit. Still another method has been proposed in which the distance to an object in the environment is measured with an ultrasonic sensor. With the method basing upon the brightness distribution, however, it is difficult to recognize in the form of three dimensions the environments. Particularly in a light intercepting method using radiation of slit lights, although it is effective for the recognition of the three dimensional configuration, the amount of data to be processed is immense so that even with a relatively large computer, the time required for one frame processing amounts to from several ten seconds to several minutes. In addition, since it is necessary to move slit lights, movable mechanical parts must be incorporated which might cause the resultant precision to be somewhat uncertain. Besides, there brings about a problem that larger energy must be supplied to a slit light source in order to recognize brighter environments.
With the method using an ultrasonic sensor, it is difficult to narrow the beam of a radiated ultrasonic wave due to its essential properties. Consequently, there is a problem that it is hard to improve the resolving power for an image.